Upload
vuthu
View
215
Download
0
Embed Size (px)
Citation preview
CHARACTERIZATION OF THE COMMERCIAL FISH PRODUCTION LANDED AT MANAUS, AMAZONAS STATE,
BRAZIL
Vandick da Silva BATISTA 1, Miguel PETRERE JÚNIOR 2
ABSTRACT: The present work aims to update a series of information about the regional fishing
production, by presenting and characterizing the contribution of the different sub-systems of
the Amazon basin to the catch landed at the main fishing market of Manaus, Brazil, from 1994
to 1996. Collectors specifically hired for this function registered key information on the
fisheries. Thirty nine types or groups of fish were found in the fishing production landed.
Jaraqui (Semaprochilodus spp.), curimatã (Prochilodus nigricans), pacu (Myleinae), matrinchã
(Brycon cephalus), sardine (Triportheus spp.), aracu (Anostomidae) and tambaqui (Colossoma
macropomum) were the most important items during three consecutive years. In 1994 these
items summed up 91.6% of the total production; in 1995 and 1996 these values were,
respectively, 85.3% and 86.4% of the total production. Tambaqui landed decreased remarkably
during the period 1976-1996. There was a strong seasonal component in the production of the
main species; jaraqui and matrinchã were mostly landed between April and June, while curimatã,
pacu, and sardine were mostly landed during the dry season. Other important items showed a
strong inter-annual variation in their production. The fishing production landed came mostly
from the sub-system of the Purus River (around 30% of the total production). The sub¬
system of the Medium-Solimões contributed with an average of 15% and the sub-systems of
the Madeira, Lower-Solimões, Upper-Amazon and Juruá, together contributed with 11.5% of
the total production landed. Finally, the remaining sub-systems contributed with only 7.6%
of the production.
KEYWORDS: fish, fisheries, Amazon, production
CARACTERIZAÇÃO DA PRODUÇÃO PESQUEIRA DESEMBARCADA PELA PESCA PROFISSIONAL EM
MANAUS, AMAZONAS, BRASIL
RESUMO : O presente trabalho visa atualizar uma série de informação sobre a produção pesqueira
regional, apresentando e caracterizando a contribuição dos diferentes sub-sistemas da Amazônia
Central para a captura desembarcada no principal mercado pesqueiro de Manaus entre 1994
e 1996. Coletores foram contratados para registrar informações chave sobre as pescarias
efetuadas. Foram registrados 39 tipos ou grupos de peixe na produção pesqueira desembarcada.
Jaraqui (Semaprochilodus spp.), curimatã (Prochilodus nigricans), pacu (Myleinae), matrinchã
1 ItesrEáíikfefefeEalcbArBzcrBS, EàaÜEkitecteCiâráasígrárias, LbHtSJ^/LázixafnriodsMiahscãtieMxjoda BEEca, (SnpjsTMAEEEitãrio, Manaus, 7M, 69077-000, e-mail: AtatJstaaitHn.e:ii.br
2 UES>, GnpusRioClaB:), Dçto. Rrilogia, Oc RsEbaLl®, Modaro , SãDftulo, 1350S-900, e-raril: npebHtBan.uBEpJta:
Am Imam 33 (1); 53-66 . 2003. 5 3
(Brycon cephalus), sardinha (Triportheus spp.), aracu (Anostomidae) e tambaqui (Colossoma
macropomum) foram os itens mais importantes durante os três anos sucessivos. Em 1994
estes itens totalizaram 91,6% da produção total; em 1995 e 1996 estes valores representaram,
respectivamente, 85,3% e 86,4% da produção total. A quantidade de tambaqui desembarcada
diminuiu notavelmente ao longo do 1976-1996. Há um componente sazonal na produção das
principais espécies: jaraqui e matrinchã foram desembarcados principalmente entre abril e
junho, enquanto que curimatã, pacu, e sardinha foram desembarcados principalmente durante
a estação seca. Outros itens importantes mostraram uma forte variação interanual na produção.
A produção pesqueira desembarcada foi originada principalmente do sub-sistema do Rio
Purus (ao redor 30% da produção total). O sub-sistema do Médio-Solimões contribuiu com
uma média de 15% e os sub-sistemas do Madeira, Baixo-Solimões, Alto-Amazonas e Juruá,
juntos contribuíram com 11,5% da produção total desembarcada. Os demais sub-sistemas
contribuíram apenas com 7,6% da produção total.
PALAVRAS-CHAVE: peixes, pesca, Amazônia, produção pesqueira.
INTRODUCTION
The knowledge about fishing in Central
Amazonia showed a great expansion at the end
of the 1970's, when a generation of researchers
developed a series of studies that rendered
pivotal information for the understanding of the
fishing activity (Petrere, 1978a/b, 1983a and
1985; Goulding, 1979 and 1981; Smith, 1979
among others), as well as about the dynamics of
the exploited populations (Petrere, 1983b;
Ribeiro, 1983; Bayley, 1983; Junk, 1984, among
others). However, during the 1980's such studies
became restricted to the contribution of Merona
and co-workers (e.g. Merona & Bittencourt,
1988; Merona & Gascuel, 1993), a situation
worsened by the interruption of the fisheries
statistics in the main fish landing market by the
INPA in 1986 and by the SUDEPE in 1988.
Only after January 1994, their work was resumed
in Manaus, this time by the Federal University
of Amazonas, Brazil.
5 4
In the present work, a part of this
information is analyzed, seeking to determine
the qualitative and quantitative evolution of
the fishing production landed in Manaus as
we l l as the t empora ry va r i a t ion of the
contribution of the different sub-systems of
the Amazon basin to the provisioning of
fishing production in this area. Such analysis
const i tu tes a way of cont r ibut ing to the
ident i f icat ion of important areas for the
development of the fishing activity; at the
same time, we hope it will supply useful
information to the ecological-economic zoning
in the area.
MATERIAL AND METHODS
Hired collectors accompanied the fishing
landed at the Feira do Panair, Manaus. They
registered the following information: dates of
arrival; name of the fishing boat; local and type
of the fishing ground; type and characteristics
Ectisba&febaeJrikr
of the gear used; number of fishermen; days
spent fishing; amount of catch per fish item
(common name of may group species); price
per type of fish; amount of fuels and lubrificants
used; and amount of ice acquired.
These collectors were also trained in
order to obtain data on fork length of at least
30 individuals per fish item per night, for 10
randomly-selected days in a month, so that
up to 300 measurements were taken during
this period. Fish product ion recorded in
numbers were transformed to weight using
mean length recorded and length-weight
r e l a t ionsh ips from va r ious papers and
unpublished reports or calculated from our
own data . The ca lcu la t ion of the catch
effectively landed followed the procedures of
Merona & Bittencourt (1988), considering that
the catch effectively landed is, in fact, 10%
higher than the one declared.
The daily level of the rivers in pre¬
selected stations per sub-system (Óbidos,
Borba, Manicoré, Parintins, Manaus, Beruri,
Canutama, Manacapuru, Maraã, Ipixuna,
Tabat inga) were supp l ied by A N E E L
(Brazilian Electric Energy Agency) for the
whole period. However, as the lack of data
for several days could seriously bias the
monthly average, we opted for taking averages
values starting from the levels registered on
the 14 t h, 15 t h and 16 t h days of each month,
considering lost the data for those months
without data for these days.
The calculation of the weight-length
regressions and of the conversion unit for
weight, and variance analyses were carried out
by statistical software, with the theoretical
background of Sokal & Rohlf (1981).
RESULTS
Landed items
Ninety-nine different common names
were registered for a variety of thirty-nine
types or groups of fish found in the fishing
p roduc t ion landed (Table 1). We also
presented, besides the common names, the
closest scientific identification.
Fish production
Table 2 presents the landed items and
the production per item for the years of 1994,
1995 and 1996, respectively. It can be noted
that j a raqu i s , curimatã, pacu, matr inchã,
sardine, aracu and tambaqui are the most
important species during three consecutive
years . In 1994 these species summed up
91.6% of the total production; in 1995 and
1996 these values were, respectively, 85.3%
and 86.4% of the total production
The data for the period 1994-1996
were plotted as a function of the production
of jaraqui, curimatã, pacu, tambaqui, matrinchã
and tucunaré (Fig. 1), along with available
information in the literature for the period
1976-1986 (Merona & Bittencourt, 1988). For
j a r a q u i , we observed an increase in the
production up to 1984-1985, with a reduction
in 1986 and stabilization, at the same levels
observed for 1980-1983, during the period
1994-1996. Curimatã was the only species
that presented a continuous increase in its
production along the studied period; pacu and
matrinchã showed a notable variation, ranging
from 200 to 400% in their productions among
consecutive years. The tambaqui production
landed showed a reduction along the historical
ser ies , albeit with occasional per iods of
Table 1 - List of the fish types found at the Manaus Fish Market, with scientific identification as detailed as possible.
Item Common Names Scientific Names Acara acará/cará/acará-preto/cará-preto/cará-branco/acará- Cichlidae (including Acarichthys heckelli, Acaronia nassa, Aequidens
branco/cará-prata s p . ; C a q u e t a i a s p e c t a b i l i s , C h a e t o b r a n c h u s f l a v e s c e n s ; C h a e t o b r a n c h o p s i s o r b i c u l a r i s , C i c h l a s s o m a a m a z o n a r u m ; Geophagus proximus, Heros sp.; Satanoperca acuticeps; S. jurupari; Symphysodon aequidens, Uaru amphiacanthoides)
Apapa apapá/sardinhão/apapá-amarelo/amarelo Pellona spp.; Ilisha amazonica; Pellona castelnaeana apapá-amarelo/amarelo Pellona castelnaeana
Aracu aracu/aracu-cabeca gorda./piau/aracu-piau Anos tomidae ( inc lud ing: Lepor inus s p p . Sch izodon fasc iatus; Anostomoides laticeps)
aracu-cabeca gorda Leporinus spp. aracu-piau Schizodon fasciatus; Anostomoides laticeps
Arraia arraia Potamotrygon/Paratrygon Aruana aruanã/lebréia/macaco d'agua/sulamba Osteoglossum bicirrhosum Bodo bodo de praia Loricariidae
bodo/acari-bodo Liposarcus pardalis Branquinha branquinha/ branquinha-cabeca-lisa/ cabeça-branca/ Cur imat idae ( inc lud ing : Po tamorh ina a l tamazon ica ; P. latior;
branquinha-cascuda/peito de aço Caeno t ropus labyr in th icus; Psect rogaster spp. ; Caeno t ropus labirinthicus)
Caparari caparari Pseudoplatystoma tigrinum Cara de gato cara de gato Platynematichthys notatus Carau-açu carau-açu/acara-açu Astronotus ocellatus; A. crassipinis Charuto charuto Anodus melanopogon; Hemiodus spp. Cubiu orana/aurana/cubiu/cubiu-orana Hemiodontidae (including: Anodus sp.; Hemiodus spp.) Cuiu-cuiu cuiú-cuiú/cujuba Oxydoras niger Cur imata curimata Prochilodus nigricans Dourada dourada Brachyplatystoma flavicans Jandia jandia/jandiar/jundia/saia-suja Leiarus marmoratus
jaraqui/jaraqui-fina/jaraqui-grossa Semaprochilodus spp. Jaraqui jaraqui-fina Semaprochilodus taeniurus
jaraqui-grossa Semaprochilodus insignis Mandi mandi Pimelodidae (including: Pimelodus spp.; Pimelodina flavipinnis;
Platysilurus cf. barbatus); Trachelyopterus galeatus Mapara mapara Hypophthalmus spp Matrinxa matrinxa/gogo/genoveva/jatuarana Brycon cephalus Pacamon jau/pacamon Paulicea luetkeni Pacu pacu/pacu-galo/ pacu-jumento Myleinae (including: Mylossoma duriventris; M. aureum; Myleus
schomburgki i ; M. torquatus; Metynnis argenteus; M. hypsauchen; Catoprion mento)
Peixe- peixe-cachorro/cachorro Rhaphiodon spp.; Acestrorhynchus spp.; Cynodon gibbus; Hydrolycus cachorro scomberoides
Peixe-lenha surubim lenha/peixe-lenha Sorubimichthys planiceps Peixe-l iso peixe-fera/peixe-liso/bagre/fera Pimelodidae (including: Brachyplatystoma spp.; Paulicea luetkeni;
Phractocephalus hemiliopterus; Pseudoplatystom spp.) Pescada pescada Plagioscion spp. Piraiba piraiba/filhote Brachyplatystoma filamentosum Piramutaba piramutaba Brachyplatystoma vaillantii Piranambu peixe-muela/moela/piranambu/barba-chata Pirinampus pirinampu; Goslinia platynema Piranha piranha Serrasalmidae (including: Pigocentrus nattereri Serrasalmus spp.) Pirapitinga pirapitinga/puta Piaractus brachypomum Pirarara pirarara Phractocephalus hemiliopterus Pirarucu pirarucu/bodeco Arapaima gigas Sardinha sardinha/sardinha-chata/sardinha-comum/ sardinha- Triportheus spp.
cumprida/sardinha-papuda sardinha-comum Triportheus albus sardinha-cumprida Triportheus elongates sardinha-papuda Triportheus flavus
Surubim surubim Pseudoplatystoma fasciatum Tambaqui tambaqui/ruelo Colossoma macropomum Tamoata tamoata/cambuti/tamuata Hoplosternum litorale Tra i ra pongo/traira Hoplias malabaricus Tucunare tucunare Cichla spp. Various various/salada Teleostei or Elasmobranchii
production recoveries; the resulting patterns
showed a consistent decrease in the period,
with an actual annual production of around
1000 tons . Tucuna ré showed a s table
production until 1980-1981, and a reduction
from the end of this period until 1986. This
pattern remained stable until 1996, with an
over-production of 800 tons in 1995-1996, a
level previously observed only in 1979.
The seasonal variation of the production
showed a peak between August and October of
1994 and 1995, a minimum between December
and March of the same years, and intermediate
values in April, June, July and November of all
5 6 Ectisba&fertaeJnkr
Table 2 - Monthly fish production corrected in tons, per item landed at the Manaus Fish Market, Manaus from 1994 to 1996.
Item 1994 1995 1996
Apapá 41,90 40,18 11,38 Aracu 2596,62 941,87 956,84 Arraia 0 1,48 0 Aruanã 370,24 391,58 401,62 Bodó 26,20 32,26 5,40 Branquinha 332,02 476,27 290,84 Caparari 8,80 13,03 8,50 Cara 156,67 162,10 18,30 Cara de Gato 0 0 86,76 10,17 Carau-Açu 59,36 89,17 12,65 Charuto 4,88 0 22,06 Cubiu 178,98 106,02 171,98 Cuiú-Cuiú 6,43 189,65 43,90 Curimatã 4689,52 3421,03 5126,76 Dourada 12,44 28,64 4,48 Jandiá 1,64 0,41 0 Jaraqui 7292,14 4722,31 6390,14 Mand i 0 0 24,22 Mapará 103,23 38,41 83,99 Matrinchã 1885,94 864,64 3270,23 Pacamão 2,02 0,20 0,18 Pacu 4755,28 2130,82 2149,44 Peixe-Liso 5,32 48,38 1,01 Pescada 187,76 277,95 105,72 Piraíba 8,79 2,16 0,79 Piramutaba 3,86 0,88 0,24 Piranambu 0 8,38 0 Piranha 54,48 18,25 0,08 Pirapitinga 269,65 242,39 1066,35 Pirarara 0,68 0,44 0,86 Pirarucu 67,13 15,80 0 Sardinha 1094,00 1716,77 1666,94 Surubim 30,21 58,61 92,22 Surubim-Lenha 0 0 31,10 1,19 Tambaqu i 656,10 5231,77 821,25 Tamoatá 0 0,39 0 Traíra 9,78 17,82 13,96 Tucunaré 160,72 871,55 766,46 Various 11,99 0 0
TOTAL 25084 22322 23589
years (Fig. 2). The month of May stands away
from this pattern, as the production during this
month was high during the three years of this
study, without configuring a tendency with the
following months. The production was higher
during the flooding period of 1996 in comparison
with the previous years, although the production
during the dry period of this year was the lowest
reported during the three years of this study.
These differences among years became evident
in Figure 3, where we observe that the
scatterplot of production against level of the river
shows a great dispersion, indicating the absence
of correlation between these variables (P>0,05).
In 1995, however, there were larger catches when
the level of the river was low and small catches
when this level was high. In 1996 there was a
lower degree of dispersion in the scatterplot than
in 1994, larger catches being recorded at high
levels of the river.
ο
ο "(Ο
ο "σ ω "σ (Ο
_ ι
15000
10000
5000
6000
3000
πΠΠπΠ jaraqui
0
4000 +
2000
0
10000
5000
0
4000
2000
α curimatã
1600
800
• Π Π Γ Π Π
matrinchã
tucunaré
ri
I I I I I I Ι — Ι ' ο 76 78 80 82 84 86 88 90 92 94 96
Year
Figure 1 . Inter-annual variation in the amount of fish (tons) landed between 1976-1988 (Merona & Bittencourt, 1988) and 1994-1996.
0
0
0
c o
ü
o T3 <u
T3 c ro
_ l
4500
4000 +
3500
3000
2500 +
2000
1500
1000
500
0 I I I I I I I I I I I I I I I I I I I I I I I I I I 7 9 11
27
24
21
1 3 5 7 9 11 1 3 5 7 9 11 1 3 5
Month
>
ai + 18
15
Figure 2 . Monthly variation in the production landed at the Manaus Fishing Harbor between January 1994 and December 1996. Dashed line refers to the mean river level at Manaus.
o A—'
o
o
ω
ro _ ι
5000
4000
3000
2000
1000
0
10 15 20 25
River level (m)
30
ο 1994
• 1995
χ 1996
Figure 3 . Dispersion diagram of the total capture landed per month versus the mean river level at Manaus, for the years 1994, 1995 and 1996.
Eva lua t ing the seasona l i t y of the
production for the most important species
(Fig. 4) we observe, as a general pattern for
the three years, that jaraqui and matrinchã
were landed mostly between April and June.
during the middle of the dry season, had an
exceptionally catch rate in 1995, starting in the
end of the flood season and ex t end ing
throughout the low water season. Aruanã
showed a high catch rate at the end of the flood
ο -t—'
ο -t—'
ο
ω ro
_ ι
2000
1500
1000
500
0 1500
1000
500
0
1500
1000
500
0
2000
1500
1000
500
0
1500
1000
500
0
- * - 94
—•—95 600
— 96 300
0
600
ο -t—'
ο -t—'
ο
ω ro
_ ι
0
400
300
150
0
200
5 6 7
Month 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2
Month
300
200
0
100
0
Figure 4 . Monthly variation of the production landed at the Manaus Fishing Harbor between January 1994 and December 1996, for the most important commercialized items.
Curimatã, pacu, sardine and, to a lesser extent,
tucunaré, were mostly landed in the low water
season, between August and November. Other
species showed peaks in their catch, which
varied in magnitude. Pirapitinga usually has a
large revenue in the drain water season
( A u g u s t - S e p t e m b e r ) , but p resen ted an
exceptional production in 1996 from May to
September. Tambaqui, which is mostly caught
season in 1994 but this pattern changed in
1995 and 1996, when most of the production
were observed at the end of the dry season
and at the beginning of the flood season,
respectively. Finally, aracu, whose production
was except ional in the drought of 1994,
showed a low production in the next drought
and a high production during the flood season
of 1996.
Origin of the fish production
The fishing production landed came
mostly from the sub-system of the Purus
River during all the studied period (around
29% of the total production - Table 3) which
was also the most visited (29% of fishing
t r ips ) . The sub - sys t em of the M e d i u m -
Solimões River contributed with an average of
14.7% of the total product ion (13.4% of
f ishing t r ips ) . The s u b - s y s t e m s of the
that there was reduction in the contribution
of the Solimões, Japurá and Jutaí Rivers, and
an increase of the contribution of the Purus,
Ju ruá , Made i r a and Negro R ive r s . The
Amazonas River did not present a noteworthy
tendency in its contribution.
D I S C U S S I O N
The amount of fish species in the
Amazon surpasses the magnitude of 1500
Table 3 . Relative participation of the sub-systems in the fishing trips done and in fishery production landed between 1994 and 1996.
% of fishing trips % of fishing production
Main sub-system 1994 1995 1996 % Total 1994 1995 1996 %Total
Purus 29.0 27.9 29.7 28.8 28.8 29.2 29.1 29 Medium Solimões 13.4 12.3 14.8 13.4 17.8 12.7 13.5 14.7 Madeira 13.5 13.5 13.1 13.4 14.8 10.2 12 12.3 Lower Solimões 20.3 12.8 11.4 16.2 17 9.8 9 11.9 Upper Amazonas 8.3 15.9 14.9 11.9 8.4 15.9 8.7 11 Juruá 3.2 7.4 6.2 5.0 3.8 15.8 9.7 9.8 Various 4.9 3.6 4.0 4.3 4.7 3.4 13.3 7.1 Negro 7.5 6.6 5.9 6.9 4.9 3.2 4.7 4.3
Madeira, Lower-Solimões, Upper-Amazonas
and Juruá, together contributed with 45% of
the total production landed, with each sub¬
system cont r ibut ing from 3.7 to 17 .4%,
depending on the year and area. Lower-
Solimões was the second most visited sub¬
system (16.2 % of fishing trips) but jus t
y ie lded 11 .9% of the total p roduc t ion ,
whereas Juruá River ranked in the fourth place
in terms of production (9.8%), although it was
only the seventh in terms of number of trips
(5%). Finally, the remaining sub-systems
contributed with only 11.4% of the production
and accounted for 11.2% of the fishing trips.
The historical variation in the landed
catch of the sub-systems is presented with a
comparison among the periods of 1976-78
(Petrere, 1982) and 1994-96 (Fig. 5). It is clear
species (Kullander, 1994 apud Junk et al.,
1997). This great richness of the Amazon fish
fauna is a general paradigm (e.g. Roberts, 1972;
Junk et al., 1997) that allows reproducing the
t rad i t iona l concept of abundan t and
permissible richness of intense economic
exploration. As far as fisheries are concerned,
there is a frequent mention to the under-
utilization of this richness, which is worsened
by the usual habit of listing several species
under a same common name. This, in turn,
leads to "species" lists with only 30 to 40
items, suggesting a low use of the variety of
existent species.
Comparing the present list with the one
assembled by Petrere (1978a), it can be noted
that it shows a higher variety of fish types;
that, can be ascribed to the registration of sub-
FiSh RtrclEtim In Ctattal Amazon 6 1
100%
80%
60% +
40%
20%
0%
//
/ / -+ 1976 1977 1978 1994 1995 1996
Year
• not identified • Negro • Jutaí • Madeira • Juruá • Amazonas • Purus • Solimões+Japurál
Figure 5 . Comparison of the relative importance of the fishing regions to the fish landed at the Manaus Fishing Harbor between 1994-1996 with those between 1976-1978, accordingly to Petrere (1982).
types within the general types listed in 1978
and whose methodological reasons are difficult
to interpret, so, it is assumed that the group
of explored species remained the same.
Considering that the diversity of the
Amazon fishes is the characterist ic most
frequently mentioned when the development
of the f ishery po ten t ia l of the area is
discussed, the traditional concentration of the
fishing on few species is often cited as an
indication of a great potential to be explored
in the area (Bayley, 1981; Pereira-Filho et al.,
1991) . However , this is an exaggera ted
concept, because there are at least 20 main
species listed during the landings in Manaus
of the commercial fishery: jaraquis (with two
spec ies and a hybr id ) , pacu (mainly
Mylossoma duriventre, but also with at least
other five species), sardine (with at least three
species of genus Triportheus), and aracus, with
at least seven species (Goulding, 1979; Santos
et al., 1984; Ferreira et al., 1996). Curimatã,
matrinchã and tambaqui, so far, consisted of
j u s t one spec ies each . This s i tua t ion ,
associated with the number of commercialized
i tems, suggests that there is at least 100
spec ies being explo i ted for commerc ia l
purposes. Also, the species more frequently
explored seem to be those with the highest
abundance. Habitats with high diversity are
associated with a low abundance per species,
or high equitability, which does favor the
multispecies commercial exploration.
In addition to this, we had over the last
20 years the expansion of the siluriforms
fishing in the Amazon area, which is linked to
the installation of freezing houses qualified for
exportation of the fishery production of the
area (Barthem & Goulding, 1997); in Central
Amazonia this process is still more recent,
being developed in the 1990s. Albeit being in
expansion, the existence of alimentary taboos
in Central Amazonia against the consumption
of species of this order, supposedly because
its meat have nega t ive p rope r t i e s , is
responsible for its small participation in the
landings at Manaus. This taboo protected this
group from being exploited in the area along
the history, a fact that is changing due to
commercial aspects and cultural influence. The
breaking of a taboo in a society represents,
on the anthropological side, a cultural change,
and on the biological-fishing side, the retreat
of the pro tec t ion to which a group was
submitted (Chapman, 1989). Once the interest
in the siluriforms appeared, the technology for
its capture quickly developed, starting from a
change of knowledge with fishermen of low
Amazon, which are experienced in the fishing
for this group (Barthem, 1990; Barthem &
Goulding, 1997). Consequently, it increased
the exploitation efficiency of the species of
this order for export purposes. Except for the
siluriforms, no other fish group commonly
caught is ostensively rejected for consumption
by local population, so the existence or not
of exploitation is a function of the availability
of marke t s and of the target spec ies in
accessible grounds.
There are none indications of changes in
the preference of the population for a given
fish type, particularly in the case of tambaqui,
according to information from fishermen and
merchants of outlets and markets of Manaus.
The market demand for tambaqui is still high,
a l though the decline in its product ion is
noteworthy and more evident when observed
along the sequences of historical production.
This species was considered under-exploited
by Petrere (1983b) until 1978, but Merona &
Bittencourt (1988) showed evidences of over-
exploitation when historical data until 1986
were analyzed and Isaac & Ruffino (1996)
recorded growth overfishing for tambaqui of
the low A m a z o n a s reg ion . The current
s i tuat ion confirms the over -explo i ta t ion
pattern; but the causes underlying this pattern
need to be elucidated.
The legal norm 08/1996 of the Brazilian
Environmental Agency - IBAMA (which
updated the legal norm n° 47 of SUDEPE)
forbids the catching of tambaqui smaller than
55 cm in total length (TL). This legislation was
reasonably executed during the 1970s, mainly
because there was enough availabili ty of
individuals of this species higher than 55 cm
TL in the fishing grounds exploited by the
fleet. More recently, only 4 1 % and 11% of
t ambaqu i l anded in 1995 and 1996,
respectively, obeyed this minimum size; in
fact, individuals with a fork length (FL) of
only 18cm could be found in the market. Given
that the size at first maturation is around 60
cm TL (Villacorta-Corrêa, 1997) and that the
species reaches at least 107 cm TL (Petrere,
1982), then we have strong indications of
growth overfishing of this species. Isaac &
Ruffino (1996) estimated the yield-per-recruit
curve for tambaqui of the Low-Amazon and
also detected growth overfishing in this area.
Payne (1987) and Villacorta-Corrêa (1997)
obtained a smaller growth rate than those
reported by the previous authors. This data
indicates that a more critical situation exists
for the Mamoré River and for the Central
Amazonia.
A s tock in the in i t ia l phase of
exploitation shows higher mean size and lower
growth rates than that subjected to a period
of intensive exploitation (Hilborn & Walters,
1992). If tambaqui stocks of the Central
Amazon have reacted to fishing exploitation,
its current value of K should be larger than it
would have been 20-30 years ago, when there
was no overfishing recorded. However, K does
not increased, imply ing that the growth
overfishing has not been strong enough to
generate responses in growth parameters or
that the species growth is not related to the
intra-specific density or abundance at the
occurred levels . On the other hand, the
occurrence of recruitment overfishing is not
clear and there indications that is not the case
yet. In the absence of up-to-date population
pa rame te r s to def ine a more effect ive
referential for the subject, the best alternative
would be to drastically reduce the catch of
juveniles and to observe the response of the
stocks in the following fishing period.
J a r a q u i s , cur imatã and ma t r inchã
characterize a different biological context from
tambaqui, as they have life-history parameters
typ ica l of r - s t ra teg i s t s (Ribe i ro , 1983;
Zaniboni, 1985; Vazzoler et al., 1989; Oliveira,
1997). The reproductive characteristics of
these spec ies do not faci l i ta te g rowth
overfishing, since juveniles are not frequently
accessible to the fishing gears most commonly
used in the area (purse and beach seines).
During up river dispersion migrations juveniles
become more vulnerable to fishing; however,
during this period, fishermen can also find
adult individuals. Moreover, some special
types of fishing gears (e.g. juvenile separator
nets) are used for the fishing of pacu and of
jaraqui (Batista, 1998), clearly indicating that
the fishermen are trying to avoid the retention
of the smaller individuals of these species.
The lack of osc i l l a t ions in the
production of curimatã and the stability in the
catch index between 1994 and 1996 (Batista,
1998) suggest that the fishing pressure has not
yet brought about perceptible effects on this
species. In contrast, jaraqui landings showed
a higher oscillation in the production and
matrinchã, as well as pacu, showed periodic
peaks in their production, with cycles of three
years for pacu and four years for matrinchã.
The gap in data from 1985 to 1993, however,
preclude assessment of the constancy in this
sequence . The marked var ia t ions in the
production of matrinchã can be either linked
to the generation of strong cohorts and/or by
env i ronmen ta l cond i t ions affect ing the
catchability of the adults (Batista, 1998).
The exceptional total production for the
month of May during the three years of this
study is associated with the downstream
migration of the fat fish, fishes with large
energy reserves for migration and reproduction
(Ribeiro, 1983; Batista, 1998). In this type of
migration, portions of the fish stock that
usually fed within the flooded forest became
available to the fishermen. On the other hand,
the small production at the beginning of the
flooding period is related to the migration
strategy employed by the characiforms during
this period. Moreover, from December until
February, IBAMA set rules prohibiting the
capture of some commercial species, which
affects the statistics.
Scan t in format ion does not a l low
assessment of defini t ive pat terns in the
regional fishery. Assembling long series data
about aquatic resources taken simultaneously
from different systems in such a broad region
like the Amazonia is very rare. Another
important subject to be considered is the noise
in the data due to the poor conditions of the
landings in Manaus, to the dynamics of the
fleet still under analyzed and to the dynamics
of the resources, better known but still lacking
some important answers. So, it is important
that the fishing exploitation be monitored in a
continuous way, and that the government and
non governmental agencies be committed with
the maintenance of the system, by allowing
technical and scientific information to be used
in the fishery sustainability in the region.
LITERATURE CITED
Barthem, R.B. 1990. Ecologia e pesca da
piramutaba (Brachyplatystoma vaillantii).
Tese de doutorado, UNICAMP, Campinas,
SP. 268 pp.
Barthem, R.B.; Goulding, M. 1997. The catfish
connection: ecology, migration and
conservation of Amazon predators.
Columbia University Press., New York. 144
pp .
Batista, V.S. 1998. Distribuição, dinâmica
da pesca e dos recursos pesqueiros na
Amazônia Central. Tese de doutorado,
INPA/FUA: 291 pp.
Bayley, P.B. 1981. Fish yield from the
Amazon in Brazil : compar isons with
African river yields and management
poss ib i l i t i e s . Transactions of the
American Fisheries Society, 110: 351-359.
Bayley, P.B. 1983. Central Amazon fish
populations: Biomass, production and
some dynamic characteristics. Tese de
doutorado, Dalhousie University. 330 pp.
Chapman, M.D. 1989. The political ecology
of fisheries depletion in Amazonia.
Environmental Conservation 16(4): 331-337.
Ferreira, E.J.G.; Zuanon, J.; Santos, G.M.
1996. A list of commercial fish species
from Santarém, State of Pará, Brazil. Naga,
19(3): 41-44.
Goulding, M. 1979. Ecologia da pesca no
Rio Madeira. INPA, Manaus. 172 pp.
Goulding, M. 1981. Man and fisheries on
an Amazon frontier. W. Junk Publications,
The Hague, 132 pp.
Hilborn, R.; Walters, C.J. 1992. Quantitative
fisheries stock assessment, Chapman and
Hall, London. 570 pp.
Isaac, V.J.; Ruffino, M.L. 1996. Population
d y n a m i c s of t ambaqu i , Colossoma
macropomum Cuvier 1818, in the Lower
Amazon, Brazil. Fisheries Management
and Ecology, (3): 315-333.
Junk, W.J. 1984. Ecology, fisheries and
fish culture in Amazonia. . In: Sioli, H.
(ed.) The Amazon: limnology and
landscape ecology of a mighty tropical
river and its basin. W. Junk Publications,
Netherlands: p. 443-476
Junk, W.J.; Soares, M.G.M.; Saint-Paul, U.
1997. The fish.. In: Junk, W.J. (ed.) The
Central Amazon Floodplain: Ecology of a
pulsing system. Ecological Studies 126: p.
385-408.
Merona, B.; Bittencourt, M.M. 1988. A
pesca na A m a z ô n i a a t ravés dos
desembarques no mercado de Manaus:
Resultados prel iminares. Memoria
Sociedad Ciencias Naturales La Salle,
48(Supl.2), 433-453.
Merona, B.; Gascuel, D. 1993. Effects of
flood regime and fishing effort on the overall
abundance of an exploited fish community
in the Amazon floodplain. Aquatic Living Resources, 6(1): 97-108.
Oliveira, M.I.B. 1997. Idade e crescimento e
aspectos da dinâmica populacional do
curimatã Prochilodus nigricans (Pisces,
Prochilodontidae) da Amazônia Central.
Dissertação de mestrado, INPA/FUA,
Manaus. 79 pp.
Payne, A.I. 1987. A preliminary stock
assessment survey of the fishery at Trinidad
in the Rio Mamoré. Relatório ODA,
Londres. 34 pp.
Pereira-Filho, M., Guimarães, S., Storti Filho,
A.; Graef, E.W. 1991. Piscicultura na
Amazônia brasi leira: entraves ao seu
desenvolvimento. In: Val, A.L.; Figliuolo,
R. & Feldberg, E. (eds.) Bases cientificas
para estratégias de preservação e
desenvolvimento da Amazônia: Fatos e
perspectivas. INPA, Manaus , AM. p.
373-380
Petrere Jr., M. 1978a. Pesca e esforço de pesca
no estado do Amazonas . II. Locais e
apare lhos de captura e es ta t ís t ica de
desembarque . Acta Amazonica
8(Suplemento 2): 1- 54.
Petrere Jr., M. 1978b. Pesca e esforço de
pesca no estado do Amazonas. I- Esforço e
captura por unidade de esforço. Acta
Amazonica 8(3): 439-454.
Petrere Jr., M. 1982. Ecology of the fisheries in
the river Amazon and its tributaries in the
Amazonas States (Brazil). Tese de
doutoramento, University of East Anglia,
Norfolk. 96 pp.
Petrere Jr., M. 1983a. Relations among catches,
fishing effort and river morphology for eight
rivers in Amazonas State (Brazil), during
1976-1978. Amazoniana, 8(2): 281-296.
Petrere Jr., M. 1983b. Yield per recruit of the
tambaqui , Colossoma macropomum
Cuvier, in the Amazonas State, Brazil.
Journal of Fish Biology, 22: 133-144.
Petrere Jr., M. 1985. A pesca comercial no
rio Solimões-Amazonas e seus afluentes:
Anál ise dos informes do pescado
desembarcado no Mercado Municipal de
Manaus (1976-1978). Ciência e Cultura,
37: 1987-1999.
Ribeiro, M.C.L.B. 1983. As migrações dos
jaraquis (Pisces, Prochilodontidae) no Rio
Negro, Amazonas, Brasil. Dissertação de
mestrado. INPA - FUA, Manaus. 192 pp.
Roberts, T.R. 1972. Ecology of fishes in the
Amazon and Congo basins. Bull. Mus.
Com. Zool., 143(2):117-147.
Santos, G.M.; Jegu, M.; Merona, B. 1984.
Catálogo de peixes comerciais do Baixo rio Tocantins. E le t ronor te /CNPq/ INPA,
Manaus. 83 pp.
Smith, N. 1979. A pesca no Rio Amazonas.
INPA/CNPq, Manaus. 154 pp.
Sokal, R.R.; Rohlf, F.J. 1981. Biometry. The
principles and practice of statistics in
biological research. W.H. Freeman and
Company, New York. 859 pp.
Vazzoler, A . E.; Amadio, S; Caraciolo-Malta,
M. C. 1989. Aspectos biológicos de
peixes amazônicos. XII. Reprodução das
espécies do gênero Semaprochilodus
(Characiformes, Prochilodontidae) do Baixo
Rio Negro, Amazonas, Brasil. Revista
Brasileira de Biologia, 49(1): 165-173.
Villacorta-Correa, M. A. 1997. Estudo de
idade e crescimento do tambaqui
Colossoma macropomum (Characi-formes,
Characidae) no Amazonas Central, pela
análise de marcas sazonais nas estruturas
mineralizadas e microestruturas nos
otólitos. Tese de doutorado INPA/FUA,
Manaus. 217 pp.
Zan ibon i -F i lho , E. 1985. Biologia da
reprodução do matrinchã, Brycon cephalus
(Gunther, 1869) (Teleostei, Characidae).
Dissertação de Mestrado, INPA/FUA,
Manaus.134 pp.
Submetido à publicação: 17/10/2000.
Aceito: 15/10/2002.
6 6 lÈt i s tH&Ki te iB Junior